African American children living in the inner city are twice as likely to be hospitalized from asthma and five times as likely to die from asthma. Results from the National Cooperative Inner-City Asthma Study (NCICAS) indicate that 77% of inner-city homes have excessive cockroach allergen concentrations. Cockroach allergen reduction, therefore, has potential public health benefits if it can be shown to affect disease morbidity. The purpose of this study is to examine the effect of cockroach extermination and cleaning on asthma morbidity in children living in the inner city of Baltimore. One hundred asthmatic children who are allergic to cockroaches will be recruited. Qualifying children enter a Baseline Phase during which they undergo an initial evaluation of symptoms, skin testing, spirometry and methacholine challenge testing. Sera will be collected for IgE and IgG antibody to cockroach. A home visit assesses roach infestation, and to measure indoor allergens in settled dust. Next, families are randomly selected to receive active treatment (insecticide, mattress covers and commercial cleaning) or to enter a control group. The control group receives no treatment until the completion of the trial. Bimonthly clinic visits continue for the next 6 months. Home visits continue every other month to inspect, set roach sticky trap samplers and collect household dust for allergen anaylsis. Methacholine challenge and serology will be repeated at 6 months. Control patients will receive extermination and cleaning at the end of the trial.